There was a story yesterday that there's an online mental health service being offered. You click your mouse, fill in a questionnaire, and they'll direct you to the nearest mental health facility to where you live. I don't have the actual website to hand, but its operated by the Department of Health. The mental health thing is in its infancy here, sure, but the awareness is definitely here.
I have ADHD, and back in the States I took adderall. Went to NTU Hospital (not sure what it stands for) and asked a psychiatrist about it, apparently Taiwan doesn't import the stuff. Don't know about ritalin, but among the three psychiatrists I've seen, all spoke adequate english, were pretty friendly and seemed professional. I recommend NTU Hospital.